{"id":168999,"date":"2024-05-08T16:36:15","date_gmt":"2024-05-08T08:36:15","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/168999.html"},"modified":"2024-05-08T16:36:22","modified_gmt":"2024-05-08T08:36:22","slug":"javascript-%e6%95%b0%e7%bb%84%e5%a6%82%e4%bd%95%e6%b1%82%e5%b9%b3%e5%9d%87%e6%95%b0","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/168999.html","title":{"rendered":"javascript \u6570\u7ec4\u5982\u4f55\u6c42\u5e73\u5747\u6570"},"content":{"rendered":"<p style=\"text-align:center\"><img decoding=\"async\" src=\"https:\/\/cdn-kb.worktile.com\/kb\/wp-content\/uploads\/2024\/04\/27035342\/c51293ba-21e1-42b8-b50d-8517e81b1727.webp\" alt=\"javascript \u6570\u7ec4\u5982\u4f55\u6c42\u5e73\u5747\u6570\" \/><\/p>\n<p><p>JavaScript\u6570\u7ec4\u7684\u5e73\u5747\u6570\u53ef\u4ee5\u901a\u8fc7\u548c\u6240\u6709\u6570\u7ec4\u5143\u7d20\u7684\u603b\u548c\u540e\u9664\u4ee5\u5143\u7d20\u6570\u91cf\u5f97\u5230\u3002\u9996\u5148\uff0c\u9700\u8981\u904d\u5386\u6570\u7ec4\u5e76\u7d2f\u52a0\u5176\u5143\u7d20\u503c\uff0c\u7136\u540e\u5c06\u7d2f\u52a0\u503c\u9664\u4ee5\u6570\u7ec4\u7684\u957f\u5ea6\u5373\u53ef\u5f97\u5230\u5e73\u5747\u6570\u3002<strong>\u4f7f\u7528<code>reduce<\/code>\u51fd\u6570\u53ef\u4ee5\u9ad8\u6548\u5730\u7d2f\u8ba1\u6570\u7ec4\u5143\u7d20\u7684\u603b\u548c\u3001\u4f7f\u7528\u6570\u7ec4\u7684<code>length<\/code>\u5c5e\u6027\u5219\u53ef\u83b7\u5f97\u6570\u7ec4\u4e2d\u5143\u7d20\u7684\u4e2a\u6570<\/strong>\u3002\u8fd9\u662f\u4e00\u79cd\u7b80\u5355\u800c\u5b9e\u7528\u7684\u65b9\u6cd5\uff0c\u5b9e\u73b0\u8d77\u6765\u65e2\u5feb\u901f\u53c8\u5bb9\u6613\u7406\u89e3\u3002<\/p>\n<\/p>\n<p><p>\u4e0b\u9762\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u6c42\u53d6JavaScript\u6570\u7ec4\u7684\u5e73\u5747\u6570\u3002<\/p>\n<\/p>\n<p><h3>\u4e00\u3001\u8ba1\u7b97\u6570\u7ec4\u5143\u7d20\u603b\u548c<\/h3>\n<\/p>\n<p><p>\u9996\u5148\uff0c\u8981\u83b7\u5f97\u6570\u7ec4\u5e73\u5747\u6570\uff0c\u9700\u8981\u8ba1\u7b97\u51fa\u6570\u7ec4\u6240\u6709\u5143\u7d20\u7684\u603b\u548c\u3002\u53ef\u4ee5\u5229\u7528<code>reduce<\/code>\u65b9\u6cd5\u6765\u7b80\u5316\u8fd9\u4e2a\u8fc7\u7a0b\uff0c\u8be5\u65b9\u6cd5\u63a5\u6536\u4e00\u4e2a\u56de\u8c03\u51fd\u6570\uff0c\u8be5\u51fd\u6570\u6709\u4e24\u4e2a\u53c2\u6570\uff1a\u7d2f\u52a0\u5668(accumulator)\u548c\u5f53\u524d\u503c(currentValue)\u3002\u901a\u8fc7\u7d2f\u52a0\u5668\uff0c\u6211\u4eec\u53ef\u4ee5\u6301\u7eed\u7d2f\u8ba1\u6570\u7ec4\u4e2d\u7684\u6570\u503c\u603b\u548c\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">function sum(arr) {<\/p>\n<p>    return arr.reduce((acc, val) =&gt; acc + val, 0);<\/p>\n<p>}<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u5728\u8fd9\u4e2a\u51fd\u6570\u4e2d\uff0c\u6211\u4eec\u521d\u59cb\u7d2f\u52a0\u5668\u7684\u503c\u4e3a0\uff0c\u5e76\u9010\u4e2a\u5c06\u6570\u7ec4\u5143\u7d20\u52a0\u5230\u7d2f\u52a0\u5668\u4e0a\uff0c\u6700\u7ec8\u8fd4\u56de\u7d2f\u8ba1\u603b\u548c\u3002<\/p>\n<\/p>\n<p><h3>\u4e8c\u3001\u8ba1\u7b97\u5e73\u5747\u503c<\/h3>\n<\/p>\n<p><p>\u6709\u4e86\u603b\u548c\u4e4b\u540e\uff0c\u53ea\u9700\u8981\u5c06\u5176\u9664\u4ee5\u6570\u7ec4\u7684\u957f\u5ea6\u5373\u53ef\u5f97\u5230\u5e73\u5747\u503c\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">function average(arr) {<\/p>\n<p>    return sum(arr) \/ arr.length;<\/p>\n<p>}<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u5728\u8fd9\u4e2a\u51fd\u6570\u4e2d\uff0c\u6211\u4eec\u9996\u5148\u4f7f\u7528\u4e4b\u524d\u5b9a\u4e49\u7684<code>sum<\/code>\u51fd\u6570\u6765\u8ba1\u7b97\u603b\u548c\uff0c\u5e76\u5c06\u7ed3\u679c\u9664\u4ee5\u6570\u7ec4\u7684<code>length<\/code>\u5c5e\u6027\uff0c\u83b7\u5f97\u5e73\u5747\u6570\u3002<\/p>\n<\/p>\n<p><h3>\u4e09\u3001\u8003\u8651\u8fb9\u7f18\u60c5\u51b5<\/h3>\n<\/p>\n<p><p>\u5728\u6c42\u5e73\u5747\u6570\u65f6\uff0c\u8fd8\u8981\u8003\u8651\u4e00\u4e9b\u8fb9\u7f18\u60c5\u51b5\uff0c\u5982\u6570\u7ec4\u4e3a\u7a7a\u6216\u975e\u6570\u7ec4\u7c7b\u578b\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5e94\u5f53\u8fd4\u56de<code>null<\/code>\u6216\u8005<code>undefined<\/code>\uff0c\u6216\u8005\u629b\u51fa\u4e00\u4e2a\u9519\u8bef\u63d0\u793a\uff0c\u4ee5\u907f\u514d\u7a0b\u5e8f\u6267\u884c\u9519\u8bef\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">function average(arr) {<\/p>\n<p>    if (!Array.isArray(arr) || arr.length === 0) {<\/p>\n<p>        return null; \/\/ \u6216\u8005\u629b\u51fa\u4e00\u4e2a\u9519\u8bef<\/p>\n<p>    }<\/p>\n<p>    return sum(arr) \/ arr.length;<\/p>\n<p>}<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><h3>\u56db\u3001\u4f18\u5316\u6027\u80fd<\/h3>\n<\/p>\n<p><p>\u867d\u7136\u4f7f\u7528<code>reduce<\/code>\u65b9\u6cd5\u5df2\u7ecf\u975e\u5e38\u9ad8\u6548\uff0c\u4f46\u5bf9\u4e8e\u5927\u578b\u6570\u7ec4\u6216\u8005\u5728\u6027\u80fd\u8981\u6c42\u8f83\u9ad8\u7684\u5e94\u7528\u4e2d\uff0c\u6211\u4eec\u53ef\u80fd\u8fd8\u9700\u8981\u8fdb\u4e00\u6b65\u4f18\u5316\u4ee3\u7801\uff0c\u6bd4\u5982\u4f7f\u7528\u5faa\u73af\u6765\u76f4\u63a5\u8ba1\u7b97\u603b\u548c\u548c\u5e73\u5747\u6570\uff0c\u51cf\u5c11\u51fd\u6570\u8c03\u7528\u4ee5\u4f18\u5316\u6027\u80fd\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">function average(arr) {<\/p>\n<p>    if (!Array.isArray(arr) || arr.length === 0) {<\/p>\n<p>        return null; \/\/ \u6216\u8005\u629b\u51fa\u4e00\u4e2a\u9519\u8bef<\/p>\n<p>    }<\/p>\n<p>    let total = 0;<\/p>\n<p>    for (let i = 0; i &lt; arr.length; i++) {<\/p>\n<p>        total += arr[i];<\/p>\n<p>    }<\/p>\n<p>    return total \/ arr.length;<\/p>\n<p>}<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><h3>\u4e94\u3001\u4f7f\u7528ES6+<\/h3>\n<\/p>\n<p><p>\u5728ES6\u53ca\u4ee5\u4e0a\u7248\u672c\u7684JavaScript\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u7bad\u5934\u51fd\u6570\u3001<code>const<\/code>\u548c<code>let<\/code>\u7b49\u7279\u6027\uff0c\u4f7f\u4ee3\u7801\u66f4\u52a0\u7b80\u6d01\u73b0\u4ee3\u3002<\/p>\n<\/p>\n<p><pre><code class=\"language-javascript\">const average = arr =&gt; {<\/p>\n<p>    if (!Array.isArray(arr) || arr.length === 0) {<\/p>\n<p>        return null; \/\/ \u6216\u8005\u629b\u51fa\u4e00\u4e2a\u9519\u8bef<\/p>\n<p>    }<\/p>\n<p>    const total = arr.reduce((acc, val) =&gt; acc + val, 0);<\/p>\n<p>    return total \/ arr.length;<\/p>\n<p>};<\/p>\n<p><\/code><\/pre>\n<\/p>\n<p><p>\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u4ec5\u529f\u80fd\u5b8c\u6574\uff0c\u800c\u4e14\u5728\u73b0\u4ee3JavaScript\u73af\u5883\u4e0b\u975e\u5e38\u9002\u7528\u3002<\/p>\n<\/p>\n<p><h3>\u516d\u3001\u603b\u7ed3<\/h3>\n<\/p>\n<p><p>\u8ba1\u7b97JavaScript\u6570\u7ec4\u7684\u5e73\u5747\u6570\u662f\u4e00\u4e2a\u5e38\u89c1\u7684\u4efb\u52a1\uff0c\u53ef\u4ee5\u901a\u8fc7\u8ba1\u7b97\u603b\u548c\u7136\u540e\u9664\u4ee5\u5143\u7d20\u6570\u91cf\u6765\u5b8c\u6210\u3002<strong>\u4f7f\u7528<code>reduce<\/code>\u65b9\u6cd5\u548c\u6570\u7ec4\u7684<code>length<\/code>\u5c5e\u6027\u662f\u5b9e\u73b0\u8fd9\u4e00\u76ee\u6807\u7684\u9ad8\u6548\u9014\u5f84<\/strong>\u3002\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u8fd8\u9700\u8003\u8651\u5230\u8fb9\u7f18\u60c5\u51b5\u5e76\u9488\u5bf9\u4e0d\u540c\u7684\u4f7f\u7528\u573a\u666f\u9009\u62e9\u5408\u9002\u4f18\u5316\u65b9\u6cd5\u3002\u901a\u8fc7\u8fd9\u6837\u7684\u6b65\u9aa4\uff0c\u53ef\u4ee5\u786e\u4fdd\u51fd\u6570\u9c81\u68d2\u3001\u9ad8\u6548\uff0c\u5e76\u9002\u5e94\u4e0d\u540c\u7684\u7f16\u7a0b\u73af\u5883\u3002<\/p>\n<\/p>\n<h2><strong>\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n<p><strong>1. \u4e3a\u4ec0\u4e48\u8981\u7528 JavaScript \u6570\u7ec4\u6c42\u5e73\u5747\u6570\uff1f<\/strong><br \/>\nJavaScript \u6570\u7ec4\u662f\u7528\u4e8e\u5b58\u50a8\u591a\u4e2a\u503c\u7684\u6570\u636e\u7ed3\u6784\uff0c\u6c42\u5e73\u5747\u6570\u80fd\u5e2e\u52a9\u6211\u4eec\u5206\u6790\u548c\u7406\u89e3\u6570\u7ec4\u6570\u636e\u7684\u6574\u4f53\u8d8b\u52bf\u3002<\/p>\n<p><strong>2. \u5982\u4f55\u901a\u8fc7 JavaScript \u6570\u7ec4\u6c42\u5e73\u5747\u6570\uff1f<\/strong><br \/>\n\u901a\u8fc7\u8ba1\u7b97\u6570\u7ec4\u5143\u7d20\u7684\u603b\u548c\uff0c\u7136\u540e\u9664\u4ee5\u6570\u7ec4\u7684\u957f\u5ea6\uff0c\u5373\u53ef\u5f97\u5230\u5e73\u5747\u6570\u3002\u53ef\u4ee5\u4f7f\u7528\u5faa\u73af\u904d\u5386\u6570\u7ec4\u5e76\u5bf9\u6bcf\u4e2a\u5143\u7d20\u8fdb\u884c\u7d2f\u52a0\uff0c\u7136\u540e\u5c06\u7d2f\u52a0\u503c\u9664\u4ee5\u6570\u7ec4\u7684\u957f\u5ea6\u3002<\/p>\n<p><strong>3. \u6709\u6ca1\u6709\u5176\u4ed6\u65b9\u6cd5\u53ef\u4ee5\u6c42 JavaScript \u6570\u7ec4\u7684\u5e73\u5747\u6570\uff1f<\/strong><br \/>\n\u9664\u4e86\u5faa\u73af\u904d\u5386\u6570\u7ec4\u7684\u65b9\u6cd5\u5916\uff0c\u8fd8\u53ef\u4ee5\u4f7f\u7528\u6570\u7ec4\u7684 reduce() \u65b9\u6cd5\u6765\u8ba1\u7b97\u6570\u7ec4\u5143\u7d20\u7684\u603b\u548c\u3002\u4f7f\u7528 reduce() \u65b9\u6cd5\u53ef\u4ee5\u66f4\u7b80\u6d01\u5730\u5b9e\u73b0\u5bf9\u6570\u7ec4\u8fdb\u884c\u7d2f\u52a0\u7684\u64cd\u4f5c\u3002\u7136\u540e\uff0c\u518d\u5c06\u6570\u7ec4\u5143\u7d20\u603b\u548c\u9664\u4ee5\u6570\u7ec4\u7684\u957f\u5ea6\u5373\u53ef\u5f97\u5230\u5e73\u5747\u6570\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"JavaScript\u6570\u7ec4\u7684\u5e73\u5747\u6570\u53ef\u4ee5\u901a\u8fc7\u548c\u6240\u6709\u6570\u7ec4\u5143\u7d20\u7684\u603b\u548c\u540e\u9664\u4ee5\u5143\u7d20\u6570\u91cf\u5f97\u5230\u3002\u9996\u5148\uff0c\u9700\u8981\u904d\u5386\u6570\u7ec4\u5e76\u7d2f\u52a0\u5176\u5143\u7d20 [&hellip;]","protected":false},"author":3,"featured_media":169010,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/168999"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=168999"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/168999\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/169010"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=168999"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=168999"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=168999"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}